BLOG: Concussion with loss of consciousness linked to higher disability rates
A substantial body of research exists on both disability and head injury, but few studies have been able to evaluate primary data on both conditions from a common broad population sample.
My colleagues and I recently conducted a cross-sectional analysis of more than 7,000 people 40 years old and older from the National Health and Nutrition Examination Surveys (NHANES). In the study — which was published in Neurology, the medical journal of the American Academy of Neurology — we specifically focused on data collected between 2011 to 2014, when the survey asked about head injury. In all, 16% of participants reported a history of head injury with loss of consciousness. The head injury could have occurred recently or many years earlier, in childhood.
The NHANES participants were asked questions about whether they had any difficulty with activities of daily living (eg, eating, dressing, chores), social/leisure activities, or mobility and physical activities such as walking up steps, standing up from an armless chair or carrying heavy objects. They were also asked whether a physical, mental or emotional problem kept them from working or limited the kind or amount of work they could do. Those who answered “yes” to these limitations or said they had “some difficulty” or greater on the activity questions were considered to have some level of disability.
Participants with a history of head injury with loss of consciousness had a significantly higher prevalence of disability compared with people without head injury (47.4% vs. 38.6%; P < .001).
The NHANES database is considered to be a representative sample of the non-institutionalized adult civilian population, so the results of this analysis are broadly generalizable to the overall U.S. population. We can say, therefore, that about 11.4 million people in the U.S. with a history of head injury have some disability, especially in the domains of mobility and work productivity. While our research doesn’t necessarily prove that their concussions caused their disabilities, the association between the two persisted even when controlling for many other factors that could affect disability rates, including age and sex, comorbidities (eg, diabetes, hypertension, history of depression) and behavioral variables (eg, smoking, physical activity, education).
The average age in the study was 58 years. Disability was more common in older adults (65 years or older) than in those 40 to 64 years old, but the impact of a prior concussion on disability was much higher in the younger age group. Although we cannot say from this study, it is possible that younger adults with disability are more likely to have limitations related to their head injury, while older adults have many potential reasons for disability.
Because the NHANES population doesn’t include active-duty military or people who are institutionalized in a prison or nursing home, there are likely more people with head injuries living with disability who aren’t counted in this sample, making the 11.4 million a low estimate.
The significant burden of disability in the concussion population suggests that more needs to be done to support or improve function in people who have suffered a head injury — especially among those with more severe injuries that include loss of consciousness.
There is much more research that needs to be done. Our study doesn’t evaluate whether the risk for disability declines with time or with specific interventions. If a concussion patient has visual or vestibular therapy to improve their balance and reduce dizziness, for example, perhaps they would have improved mobility and be less likely to report disability in that domain. We would certainly like to see prospective studies to determine whether rehabilitation after head injury mitigates risk.
In the meantime, clinicians who are caring for people who have suffered a concussion with loss of consciousness should ask about their level of function and be aware that these individuals may be at higher risk for disability.
Reference:
- Schneider ALC, et al. Neurology. 2021;doi:10.1212/WNL.0000000000012148.
For more information:
Andrea L. C. Schneider, MD, PhD, is assistant professor of neurology at the University of Pennsylvania. She specializes in spinal cord injury and traumatic brain injury, with a special interest in the relationships among TBI, cognitive decline and dementia risk. She is a member of the National Neurotrauma Society and serves on the NFL Players Association Mackey White Health and Safety Committee.
Disclaimer: The views and opinions expressed in this blog are those of the authors and do not necessarily reflect the official policy or position of the Neuro-Optometric Rehabilitation Association unless otherwise noted. This blog is for informational purposes only and is not a substitute for the professional medical advice of a physician. NORA does not recommend or endorse any specific tests, physicians, products or procedures. For more on our website and online content, click here.
Collapse